Re: "two monitors plugged into each other, a USB mouse plugged in to an ethernet port"
I once worked with a developer who plugged his ethernet connection into his monitor port. I can't remember what adaptors were in use, but this was a while back so they must have been pretty funky.
Unsurprisingly the entire network went down immediately. It took a while before someone realised that his complaining about his monitor not working, and everyone else complaining about the network not working, were directly related.